lib/libc/stdlib/_strtol.h

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * Original version ID:
  30  * $NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp $
  31  */
  32
  33 #define _LOCALE_NAME(func) func ## _l
  34 #define _MAKE_LOCALE_NAME(func) _LOCALE_NAME(func)
  35 #define _FUNCNAME_L _MAKE_LOCALE_NAME(_FUNCNAME)
  36
  37 /*
  38  * function template for strtol, strtoll and strtoimax.
  39  *
  40  * parameters:
  41  *      _FUNCNAME : function name
  42  *      __INT     : return type
  43  *      __INT_MIN : lower limit of the return type
  44  *      __INT_MAX : upper limit of the return type
  45  */
  46 __INT
  47 _FUNCNAME_L(const char * __restrict nptr, char ** __restrict endptr, int base,
  48                 locale_t locale)
  49 {
  50         const char *s;
  51         __INT acc, cutoff;
  52         char c;
  53         int i, neg, any, cutlim;
  54
  55         _DIAGASSERT(nptr != NULL);
  56         /* endptr may be NULL */
  57
  58         FIX_LOCALE(locale);
  59
  60         /* check base value */
  61         if (base && (base < 2 || base > 36)) {
  62                 errno = EINVAL;
  63                 return(0);
  64         }
  65
  66         /*
  67          * Skip white space and pick up leading +/- sign if any.
  68          * If base is 0, allow 0x for hex and 0 for octal, else
  69          * assume decimal; if base is already 16, allow 0x.
  70          */
  71         s = nptr;
  72         do {
  73                 c = *s++;
  74         } while (isspace_l((unsigned char)c, locale));
  75         if (c == '-') {
  76                 neg = 1;
  77                 c = *s++;
  78         } else {
  79                 neg = 0;
  80                 if (c == '+')
  81                         c = *s++;
  82         }
  83         if ((base == 0 || base == 16) &&
  84             c == '0' && (*s == 'x' || *s == 'X')) {
  85                 c = s[1];
  86                 s += 2;
  87                 base = 16;
  88         }
  89         if (base == 0)
  90                 base = c == '0' ? 8 : 10;
  91
  92         /*
  93          * Compute the cutoff value between legal numbers and illegal
  94          * numbers.  That is the largest legal value, divided by the
  95          * base.  An input number that is greater than this value, if
  96          * followed by a legal input character, is too big.  One that
  97          * is equal to this value may be valid or not; the limit
  98          * between valid and invalid numbers is then based on the last
  99          * digit.  For instance, if the range for longs is
 100          * [-2147483648..2147483647] and the input base is 10,
 101          * cutoff will be set to 214748364 and cutlim to either
 102          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 103          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 104          * the number is too big, and we will return a range error.
 105          *
 106          * Set any if any `digits' consumed; make it negative to indicate
 107          * overflow.
 108          */
 109         cutoff = neg ? __INT_MIN : __INT_MAX;
 110         cutlim = (int)(cutoff % base);
 111         cutoff /= base;
 112         if (neg) {
 113                 if (cutlim > 0) {
 114                         cutlim -= base;
 115                         cutoff += 1;
 116                 }
 117                 cutlim = -cutlim;
 118         }
 119         for (acc = 0, any = 0;; c = *s++) {
 120                 if (!isascii(c))
 121                         break;
 122                 if (isdigit(c))
 123                         i = c - '0';
 124                 else if (isalpha(c))
 125                         i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
 126                 else
 127                         break;
 128                 if (i >= base)
 129                         break;
 130                 if (any < 0)
 131                         continue;
 132                 if (neg) {
 133                         if (acc < cutoff || (acc == cutoff && i > cutlim)) {
 134                                 any = -1;
 135                                 acc = __INT_MIN;
 136                                 errno = ERANGE;
 137                         } else {
 138                                 any = 1;
 139                                 acc *= base;
 140                                 acc -= i;
 141                         }
 142                 } else {
 143                         if (acc > cutoff || (acc == cutoff && i > cutlim)) {
 144                                 any = -1;
 145                                 acc = __INT_MAX;
 146                                 errno = ERANGE;
 147                         } else {
 148                                 any = 1;
 149                                 acc *= base;
 150                                 acc += i;
 151                         }
 152                 }
 153         }
 154         if (endptr != NULL)
 155                 /* LINTED interface specification */
 156                 *endptr = __DECONST(char *, (any ? s - 1 : nptr));
 157         return(acc);
 158 }
 159
 160 __INT
 161 _FUNCNAME(const char * __restrict nptr, char ** __restrict endptr, int base)
 162 {
 163         return _FUNCNAME_L(nptr, endptr, base, __get_locale());
 164 }